Cyclopentadiene, cyclopentene and cyclopentane and alkylated derivatives thereof are known in the art. Further, methods are known for preparation of alkylated cyclopentadienes and conversion of these materials to cyclopentenes and cyclopentanes. There is substantial interest in cyclopentadienes, cyclopentenes, and cyclopentanes since cyclopentadiene is characterized by the unique property of being the most acidic aliphatic hydrocarbon known, having a pKa of 18, and also because its reactions as a Diels-Alder diene are extremely facile. Because of the aromaticity of the cyclopentadiene anion (c--C.sub.5 H.sub.5.sup.-), cyclopentadiene is easily the most acidic of the simple hydrocarbons and in fact is comparable in acidity to alcohols. This means that substantial amounts of the anion can be generated with alkoxides and even concentrated solutions of hydroxide. Since it is uniquely stable, it can participate in the carbanion reactions of alkylation, acylation, carboxylation and the like.
U.S. Pat. No. 3,255,267 to Fritz et al discloses the alkylation of cyclopentadiene and monoalkylcyclopentadiene with a single primary or secondary alcohol in the presence of a highly alkaline catalyst, including the disclosure of trialkylated and tetralkylated products. Fritz et al do not appear to contemplate using mixed alcohols for alkylation and the alkylcyclopentadiene products disclosed cannot have more than two different alkyl groups, a single substituent derived from starting cyclopentadiene and the rest derived from the alcohol.
The cyclopentadienes described by Fritz et al contain primary hydrocarbon substituents of up to 11 carbon atoms and secondary hydrocarbons of structure R.sub.c R.sub.d CH, where R.sub.c is selected from "hydrocarbon radicals free of aliphatic unsaturation, including alkyl and aryl radicals, said radicals having from 1 to 10 carbon atoms;" and R.sub.d is "a hydrocarbon radical free of aliphatic unsaturation, including alkyl and aryl radicals, said radicals having from 1 to 10 carbon atoms;". An additional class includes R.sub.c R.sub.d =--CH.sub.2 (CH.sub.2).sub.n CH.sub.2 -- where n is an integer having a value of 1 to 10. Thus, Fritz et al teach compositions in which no more than two different kinds of hydrocarbyl groups may be present, and in which no more than one hydrocarbyl group may occur more than once. Thus, the products which can be produced by Fritz et al are controlled by this disclosed alkylation reaction which uses only a single alcohol. In addition, Fritz et al teach that "Ethanol is by far the preferred primary alcohol since the yields obtained with this alcohol are much in excess of the yields obtained when employing other primary alcohols." Fritz et al present two examples of alkylation with primary alcohols with the following yields based on cyclopentadiene: